Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Digital holography (DH) can be used, for example, in bio-imaging, microscopy, optical metrology, phase contrast and quantitative phase imaging and nondestructive imaging applications. Digital holography systems can include a sensor array for recording of a hologram or an interference pattern between a reference beam and an object beam derived from a light source for obtaining image data associated with an object. Such systems can have image reconstruction algorithms to reconstruct images from the image data.
Sensor array detectors, such as charged-coupled device (CCD) or complimentary metal-oxide semiconductor (CMOS) device, can be used in a digital holography system. In such systems, the image reconstruction algorithms can be similar to physical hologram reconstruction algorithms. As a result, the recovered images can include artifacts such as corresponding to dc and twin image terms of the obtained hologram when a single hologram frame is used for image recovery. Further the image resolution in off-axis digital holography can be limited by a minimum reference beam angle condition that is required in order to separate the dc and cross terms in the interference pattern in the Fourier transform domain. In certain digital holography systems, multiple hologram frames may be required to achieve high resolution images of the imaged object. Such systems may not be able to provide live (e.g., real-time) high resolution imaging of the object.
In certain imaging applications, brightfield microscopes can be used to obtain images of transparent objects such as live biological cells. In such applications, contrast agents such as a dye or fluorescent labels can be applied (e.g., staining) to the objects that may be difficult to be visualized solely by transmission of light through the object. The application of the contrast agent can damage the objects (e.g., the cells). In certain other imaging applications, three-dimensional imaging of objects can be performed using laser scanning confocal microscopes, which can be substantially expensive compared to brightfield microscopes.